Synthesis, characterization and spectroscopic properties of some rare earth activated LiAlO2 phosphor

Abstract

The current paper comprises the synthesis of LiAlO 2 phosphor doped with rare-earth elements Tb 3+ , Eu 3+ , and Dy 3+ by microwave-assisted solution combustion synthesis method (SCS) and the spectroscopic properties were examined. The phosphors samples were identified and characterized by XRD, FT-IR, thermo-gravimetric analysis TG-DTA and SEM. All the prepared phosphors show polycrystalline nature with a grain size of about 49 nm as confirmed from XRD and SEM. Photoluminescence excitation and emission spectrum of Tb 3+ , Eu 3+ , and Dy 3+ doped LiAlO 2 with different sintering temperature and concentration of dopants were investigated. The Dy 3+ shows the strongest blue emission peak at 484 nm corresponding to the transition 4 F 9/2 to 6 H 15/2 under UV excitation of 358 nm. The Eu 3+ doped LiAlO 2 phosphor shows emission peak 591 nm to 615 nm for UV excitation of 238 nm which arise due to 5 D 0 to 7 F 1 electric dipole transitions. The Tb 3+ doped phosphor shows a broad excitation peak centered at 238 nm whereas it exhibits an emission peak at 544 nm corresponding to the peak transition 5 D 4 - 7 F 6 under the UV excitation at 238 nm.